The explosive discharge of small, sharp plastic toys that occurs at children's parties and holiday events.

Derives from shrapnel + cheap plasti-krap, a description which encompasses both the sharp, weapon-like properties of the toys and their uselessness, and thus propensity to scatter on the floor of children's rooms where they cut parents' bare/stocking feet.

Watch out for crapnel; there were goody bags at the party.

OR

Wendy's foot required three stitches when some Halloween crapnel rolled into her open-toed Keens.